Vacuum cleaners



March 26, 1963 c. G. FRANTZ 3,082,940

VACUUM CLEANERS Filed. March 29, 1960 2 Sheets-Sheet 1 INVENTOR. CLARENCE G. FRANTZ BY R/C HE X M /|/1'/l//1/V'VW/BFl/VG 70/? A TT'OR/VE March 26, 1963 c. G. FRANTZ VACUUM CLEANERS 2 Sheets-Sheet 2 Filed March 29, 1960 INVENTOR. CLARENCE G. FRANTZ BY RIOS EX M /VENA/WFAR/P/NGTO/D United States Patent This invention relates to vacuum cleaners and more particularly to a novel and improved vacuum cleaner motor and fan unit particularly adapted for use in a lightweight, compact cleaner having the combined advantages of a conventional floor cleaner and a hand cleaner.

Conventional floor cleaners are of two general types, a stick type wherein the floor nozzle is directly connected to the cleaner and is guided by a stick or rigid elongated handle and a cylinder or canister type wherein the floor nozzle is connected to the cleaner by a flexible hose. In both types, various attachments are usually available for different kinds of cleaning. However, both types are relatively heavy and generally weigh in excess of pounds. Due to the weight and size of these cleaners they cannot be easily lifted for oif-the-fioor cleaning and are awkward to use for cleaning stairs and the like.

I have devised a novel and improved light-weight, compact hand unit which can be incorporated in a stick type vacuum cleaner having a weight of approximately six pounds which is adapted to function as a conventional floor cleaner. Due to its relatively small size and weight, it is particularly adapted for cleaning stairs and the like.

Also due to its weight and size, it can in efiect be used as a wand with various attachments for otf-the-fioor cleaning such as for cleaning draperies, picture frames, Venetian blinds, and the like.

It is an important object of this invention to provide a novel and improved vacuum cleaner motor fan unit constructed and arranged so that the heat dissipation from the motor is accomplished by conducting the heat from the motor casing to the air stream without necessitating the movement of cooling air through the motor.

It is another important object of this invention to provide a novel and improved vacuum cleaner motor fan unit wherein the motor housing prevents flow of cooling air therethrough and the unit is constructed and arranged to dissipate motor heat by conduction out of the housing to the air around such housing.

It is still another object of this invention to provide a novel and improved motor fan unit for vacuum cleaners wherein a heat conductor path is provided to conduct heat from the bearing zone of the motor to the air fiowing past the motor eliminating the necessity of cooling air flow through the motor housing.

it is still another object of this invention to provide a novel and improved vacuum cleaner motor fan unit and mounting therefor incorporating resilient insulating support elements for the motor fan unit having fiat forward faces extending radially from the motor fan unit combined with rearwardiy extending lugs on the fan extending to a position closely adjacent to the support elements and operating to cut and shread material between the lugs and the support elements thereby preventing the accumulation of thread-like material in said unit.

it is still another object of this invention to provide a novel and improved motor ran unit for vacuum cleaners incorporating means on the motor support and fan cooperating to shread thread-like material preventing its accumulation in the unit.

Further objects and advantages will appear from the following description and drawings wherein FIGURE 1 is a perspective view of the vacuum cleaner embodying the invention and adapted for use as a floor cleaner;

FIGURE 2 is a perspective view of the motor fan unit including the resilient mounting and air guide means;

FlGURE 3 is an elevational View with parts in section of the unit shown in FIGURE 2; and

FIGURE 4 is a left-end view of the unit shown in FEGURE 3.

Referring now to the drawings, the cleaner is generally indicated at l0 and is shown with the parts assembled for use in a conventional manner as a floor cleaner. The cleaner comprises a partially cylindrical dust bag receptacle lit, a dust bag 12, a fan housing 13, a floor nozzle 14, and a stick or handle 16 detachably secured to the receptacle ill. The handle 16 is preferably formed of wood and has a lower L-shaped hook 17 threaded or otherwise secured thereto and an upper hook 18 which is generally lJ-shaped with an inclined prong extending downwardly from the upper leg of the U-shaped portion. When the cleaner is not in use, the motor cord 21 may be looped over the hooks 1'7 and 18 and the cleaner which as previously explained has a weight of approximately six pounds may be hung in a storage closet by slipping the upper hook 13 over a peg or hook in the storage space. The cord is provided with the conventional plug 22 and a finger switch 23.

The bag receptacle 11 is preferably formed of sheet metal with the lower portion generally being cylindrical and the upper portion gradually varying from cylindrical to generally semi-cylindrical whereby the base of the upper portion is open for easy insertion and removal of the dust bag 12. The edge forming the opening is provided with a rubber or the like trim strip 24. A bag support strip 25 is connected to the receptacle in any suitable manner as by rivets. Preferably formed integral with the receptacle is a raised top section including a semi-tubular portion 27, a shallow U-shaped portion 28 and slightly enlarged U-shaped end portion 29. Fixed to the inner wall of the portion 27 is a short metal tube 31 which has a slot 32 at its outer end adapted to receive a finger 33 and a latch 36. The handle 1-5 is adapted to have its end portion telescoped within the tube 31 and for ease of insertion and to avoid wear, the handle portion is provided with a metal sleeve or collar. The latch 36 operates to connect the handle re to the receptable l1 and is depressed to permit removal of the handle. A hand strap 31' extends between the end portion 29 and the fan housing 13 and is used to carry the cleaner when it is operated as a hand cleaner.

Referring to FIGURES 2, 3 and 4, the motor fan unit is indicated generally at 51. The motor 52 is fully enclosed preferably having a speed of 15,000 rpm. The motor shaft 53 projects through an end plate which is bolted to the motor and has a rearwardly extending circular flange 54 loosely telescoped over the end of the motor housing and a forwardly extending aligned circular flange or ring 56 extending into a recess formed in the fan 57. The fan is conventional in having a conical face 58 from which curved or off-set blades 59 extend to the face periphery and with the blade outer edges 61 being generally parallel to the fan axis. However, extending rearwardly from the face 58 and in alignment with the blade edges 61 are a plurality of block-form shreading lugs 62. These lugs extend closely adjacent the fiat faces 63 of a pair of rubber or the like mounting elements 64'.

The tolerance between the ring 56 which is fixed to the motor 52 and the fan recess into which the ring partially extends, including the inner face of the lug 62 is very close being approximately ten-thousandths (.010) of an inch. The shreading lugs are ground or formed to have knife edges at the lug corners and this fact, coupled with the close tolerance, minimizes any tendency of threads and the like to wind around the ring 56 or of dust or dirt to build up on the ring. Further, any threads,

0.3 cloth particles or the like, which tend to lodge between the fan and the mounting elements 64 are shreaded between the lugs 62 and the element faces 63.

It will be understood that each element 64 provides a resilient surface at the face 63 which is adjacent'the rear or trailing edge of the shreading lugs 62. The shreading lugs 62 move in a' circular or rotary path along the face 63 and accordingly, the shreading action in this area is characterized by a' rigid metal lug working against a resilient surface. The resilience of the surface tends to bias threads, cloth particles, or the like, toward the lugs 62.

It will be noted that the motor shaft 53 which is preferably pin connected to the fan hub 66 is slightly inset from the outer face of the hub, thus avoiding any tendency of thread-like material to wrap around the motor shaft. Extensive tests have indicated that the above described arrangement practically eliminates service trouble due to material drawn into the cleaner building up on parts of the motor fan unit 51.

The mounting elements 64- Which hold the unit 53 in electrical insulating spaced relationship to the fan housing 13, and receptacle 11, not only cushions the motor to minimize transmission of vibration but serves as air guides or vanes. It will be noted that the elements 64 are generally V-shaped in longitudinal contour and have slightly curved side walls 67 and that the top or outer wall is stepped whereby surface 68 is slightly spaced from the inner Wall of the receptacle 11 and the surface 69 abuts the wall. Also, it will be noted that each element has a lateral extension of reduced thickness as indicated at 71.

Each element has four holes formed therein including a hole'through the extension. The holes indicated at 72 and'73 are adapted to receive screws '74 which engage end plate flange 54 to secure the elements to the motor 52 or unit 51. The fan case 13 has a rearwardly extending flange 76 adapted to seat on the element surface 68 and abut the circular shoulder formed between the element surfaces 63 and 69. As best illustrated in FIGURE 4, element holes 73 are countersunk so that the head of screw 74 is spaced from flange 76 and due to the reduced thickness of the extension 71, the head of screw 74 inserted in the hole 72 is also spaced from this flange. It will be noted by reference to FIGURE 2 that each element has a V-shaped projection 77 extending from its circular shoulder adaptedto engage corresponding notches (not shown) at the rear edge of the fan case flange 76 to assist in properly aligning the case with the elements 6 during assembly and to aid in resisting any twisting tendency of the motor. The element holes 7-9 and 75 have tubular metal inserts extending to square-head nuts embedded in the rubber at the base of the holes.

As best shown in FiGURE 3, the forward end of the receptacle 11 is telescoped over the fan case flange 76' and screws 77 projected through the openings in the re ceptacle and the flange engage the nuts to screw these parts to the elements 64..

It will now be understood that since the screws 74 which secure the rubber elements 64- to the motor fan unit 51 only contact the elements and the unit, screws 77 only contact the'elements and the fancase 13 and receptacle 11, and the screws are spaced along the elements, the unit is etliciently insulated electrically from allof the external parts of the cleaner.

In addition to providing electrical insulation, the rubber elements 64 form a cushioning or resilient mounting for the motor fan unit 51 and act as air vanes. Dirt laden air drawn into the fan case 13 is directed radially outwardly into the space between the revolving fan blades 59 and the rear wall portion of the fan case. The air is then forced under pressure through the two curved openings indicated at 78. Openings 73 are formed by the end plate flanges or rings 54- a-nd56 defining a radially inner curved wall, the fan case flange 76 as a curved radially outer wall, and the forward lateral projections of the elements 64 as end walls. After passing through the opening 7%, the air enters in large passages defined by the wall of the receptacle 11 as a radially outer wall, the shell or housing of the motor 52 as a radial inner wall, and the curved sides 67 of the elements 64 as end walls. Thus the whirling air is first directed through the restricted opening '78 and then rearwardly over the motor through generally enlarged passages. This has the effect of converting the whirling motion of the air at the fan zone into substantially linear motion before the air reaches the dust bag. Since the whirling or turbulent motion of the air is converted to linear motion by directing the air through a restricted opening into an enlarged passage. For well recognized reasons, it is highly desirable that the air enter the dust bag with a minimum of turbulence.

As best illustrated in FIGURE 3, a flat ring 81 is Welded or otherwise secured to the inner wall of the receptacle 11 adjacent the receptacle opening provided for insertion and removal of the dust bag 12. The ring is provided with a plurality, of preferably three, circumferentially spaced and inwardly projecting pin 82 adapted to detachably lock a bag collar 83 in place. The collar 33 is preferably formed of molded plastic and COIllprises a circular flange 84 adapted to tightly telescope within the ring 81, a frusto-conical portion 36 extending from the flange 84- to a reduced tubular neck portion 87, and a shoulder circular rib 83 adapted to abut the rear edge of the ring 81. The collar flange 84 is formed with L-shaped or bayonet type slots for engagement with the pins 82. To avoid accidental detachment or loosening of the collar 83, I preferably provide a screw 89 which is threaded through the receptacle 11 and ring 31 to engage collar flange 84.

The elements 64 have oblong openings 91 therein through which the cord 21 extending from the motor may be projected to extend through an opening in the receptacle 11. A conventional nylon or the like bushing 92 is adapted to be forced through the receptacle openin and into the element opening 91.

As previously described, the motor 52 has an end plate comprising the aligned circular flanges 54 and 56, the end plate preferably being formed of two similar flanged discs welded together and formed with a central opening through which the motor shaft 53 projects. Also, the motor preferably has a speed of about 15,000 rpm. since I have found that a relatively small and light-weight motor can create a desirable suction or air flow at this speed when directly connected to the fan. Motors of this type are usually provided with a sleeve bearing for the motor shaft which is mounted in the forward end wall of the motor housing. At this shaft speed, dissipation of heat generated at the bearing zone creates a problem. I have found that if the end plate is formed of a high-heat conducting metal and either directly connected :to the shaft hearings or extending in abutting relationship with the front wall of the motor housing at a point closely adjacent the shaft bearings, the motor temperature can be kept below an acceptable level. This is due to the fact that the end plate flanges '54 and 56 form the lower wall of the air passage openings 73 and since the rate of air flow is greatest through the openings, heat conducted to the end plate flanges is rapidly removed by the relatively cool air flowing over the flanges. In other words, the bearing heat is directly conducted to zones wherein the entire volume of moving air flows at the fastest rate.

It will be noted by reference to FIGURE 4- that the openings 78 have a cross-sectional area at least equal to the area of the element faces 63. Therefore, the openings comprise at least half the cross-sectional space between the cleaner sheil and the motor or between the shell and end plate flanges 54 and :16. l have found that if the cross-sectional areas of the openings '78 are at least equal to one-half of the available cross-sectional area between the shell and flanges '54 and 56, relatively free flow of air through the cleaner is maintained and sufficient portions of the flanges are exposed to contact with the flowing air to provide a desirable heat exchange.

Although a preferred embodiment of this invention is illustrated, it is to be understood that various modifications and rearrangements of parts may be resorted to without departing from the scope of the invention as defined in the following claims.

What I claim is as follows:

1. In a vacuum cleaner of the type comprising a shell, a motor-fan unit within the shell and spaced from the wall thereof, a motor housing preventing flow of cooling air through said motor, the fan being directly connected to the motor by a high speed shaft, and a hearing for the shaft in the front end wall of the motor, the combination of means providing spaced air flow openings between the motor side wall and shell adjacent the front end of the motor, the cross-sectional area of said openings comprising at least one half of the total cross-sectional area between the motor and shell at the location of said openings, an end plate formed of high heat conducting material disposed between the motor and fan, the end plate initiating at least closely adjacent to said bearing and in heat conducting relation therewith, said end plate having an axially extending peripheral flange forming a wall at said air flow openings, and the said openings being restricted relative to the air flow space forwardly and rearwardly thereof creating a relatively high rate of air flow through the openings whereby heat generated at the bearing zone and conducted to said flange will be in heat exchange relation with air flowing through said openings.

2. In a vacuum cleaner having a shell, a relatively high speed electric motor enclosed within a housing preventing a flow of cooling air therethrough, a shaft projecting from the forward end wall of the motor, a hearing for the shaft mounted in said end wall, and a fan secured to said shaft, the combination of an end plate formed of high heat conducting material secured to the motor having a peripheral flange, said end plate being disposed between the motor and fan and extending radially inwardly at least closely adjacent the shaft bear ing, circumferentially spaced mounting elements disposed between said end plate flange and shell, saidrnounting elements having radially extending forward faces and side walls, said elements together with the shell and said end plate flange forming restricted openings through which substantially all the air from the fan is directed, and the cross-sectional area of said openings being at least equal to the cross-sectional area of said element forward faces whereby heat generated at the bearing zone will be conducted by the end plate to said restricted openings effecting heat exchange with air having a high rate of flow through said openings.

3. A vacuum cleaner comprising a shell having an inlet adapted to be connected to a cleaning tool and an outlet adapted to be connected to a dust bag, a motorfan unit in said shell intermediate said inlet and outlet, a plurality of peripherally spaced resilient electrically insulating support elements extending between said shell and motor-fan unit supporting said motor-fan unit within said shell in a position spaced therefrom, each element having a flat forward face extending radially from said motor-fan unit, and the fan having rearwardly extending lugs closely adjacent said faces whereby thread-like material drawn into the cleaner tending to wrap around the fan is shredded between the lugs and said resilient element faces.

References Cited in the file of this patent UNITED STATES PATENTS Re. 21,847 Bernfeld July 1, 1941 1,184,485 Mummert May 23, 1916 1,797,455 Vose Mar. 24, 1931 1,806,177 Pardee May 19, 1931 1,878,858 Kitto Sept. 20, 1932 1,884,871 Riebel Oct. 25, 1932 2,223,847 Engdahl Dec. 3, 1940 2,224,205 Whitaker Dec. 10, 1940 2,245,989 Leathers June 17, 1941 2,311,369 Clements Feb. 16, 1943 2,352,206 Kendall lune 27, 1944 2,570,759 Bramhall Oct. 9, 1951 2,658,228 Meycrhoefer Nov. 10, 1953 2,674,405 Cawl Apr. 6, 1954 2,722,285 Brace Nov. 1, 1955 2,744,679 Howard May 8, 1956 2,749,024 Wilfert June 5, 1956 2,870,863 Bramhall Jan. 27, 1959 FOREIGN PATENTS 261,780 Great Britain Feb. 20, 1928 367,077 Great Britain Feb. 18, 1932 545,233 Great Britain May 15, 1942 1,079,501 France May 19, 1954 

3. A VACUUM CLEANER COMPRISING A SHELL HAVING AN INLET ADAPTED TO BE CONNECTED TO A CLEANING TOOL AND AN OUTLET ADAPTED TO BE CONNECTED TO A DUST BAG, A MOTORFAN UNIT IN SAID SHELL INTERMEDIATE SAID INLET AND OUTLET, A PLURALITY OF PERIPHERALLY SPACED RESILIENT ELECTRICALLY INSULATING SUPPORT ELEMENTS EXTENDING BETWEEN SAID SHELL AND MOTOR-FAN UNIT SUPPORTING SAID MOTOR-FAN UNIT WITHIN SAID SHELL IN A POSITION SPACED THEREFROM, EACH ELEMENT HAVING A FLAT FORWARD FACE EXTENDING RADIALLY FROM SAID MOTOR-FAN UNIT, AND THE FAN HAVING REARWARDLY EXTENDING LUGS CLOSELY ADJACENT SAID FACES WHEREBY THREAD-LIKE MATERIAL DRAWN INTO THE CLEANER TENDING TO WRAP AROUND THE FAN IS SHREDDED BETWEEN THE LUGS AND SAID RESILIENT ELEMENT FACES. 